共查询到20条相似文献,搜索用时 62 毫秒
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针对传统移动曲面拟合滤波算法难以使用单一且具有自适应性阈值滤波的问题,提出一种改进自适应阈值滤波算法.首先将点云格网化,利用混合最小二乘曲面拟合对多级移动曲面滤波算法进行部分优化;其次利用离散点云数据分布特征计算一级滤波阈值;最后计算格网中最大真实高程值与最小真实高程值之差,利用曲率极限点为该值设定一个自适应系数,对滤... 相似文献
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机载激光雷达点云数据滤波技术是LiDAR数据后处理最关键的内容之一。利用最小二乘平差的曲面拟合滤波算法存在一定不足,基于混合最小二乘和总体最小二乘的算法可以有效弥补不足。本文提出一种基于混合最小二乘和总体最小二乘的曲面拟合滤波算法。实验表明,本文滤波算法效果良好,满足实际应用需求。 相似文献
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传统曲面约束滤波算法中,利用最小二乘拟合地形曲面易受种子点粗差影响。针对这一问题,提出基于抗差趋势面的机载激光雷达点云数据滤波方法,首先构建格网索引组织数据,引入抗差趋势面拟合合理的区块地形,通过自适应阈值的设置实现不同区域的自动灵活处理,最终滤除孤立点完善滤波结果。使用ISPRS提供的测区数据进行实验,与传统曲面拟合方法进行对比,实验结果证明,该方法较传统移动曲面拟合法能够得到更加可靠的滤波结果,具备较高实用价值。 相似文献
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陈森 《测绘与空间地理信息》2023,(11):157-159+162
针对传统的点云滤波算法存在阈值单一、地面点提取准确低的问题,本文提出了一种改进自适应阈值滤波算法。首先通过对点云数据进行二维投影并进行格网化处理;其次通过格网内最低点进行混合最小二乘曲面拟合;最后通过一级滤波阈值与自适应阈值实现非地面点滤波。为了对本文提出的自适应阈值滤波算法的有效性进行检验,分别使用城市中心道路与郊区道路点云数据进行算法实验。结果表明,本文提出滤波算法对城市中心道路点云滤波结果的一类误差、二类误差、总误差分别为4.6%、2.3%、3.7%;对郊区道路点云滤波结果的一类误差、二类误差、总误差分别为5.4%、7.1%、6.5%。相比于传统的移动窗口滤波算法,本文滤波算法无论是一类误差、二类误差还是总误差均更低,可准确区分出地面点与非地面点,表现出了更好的点云滤波性能。 相似文献
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数字交通发展要求开展公路路面数字化,路面数字化主要采用车载或机载激光扫描,但由于遮挡等原因,路面扫描容易产生大小不一的数据空洞。为了处理激光扫描点云数据中空洞,文中提出公路路面空洞插补的移动最小二乘平面拟合方法,即将公路细分为许多格网区域,并视单个格网近似为平面,采用格网内实测点云拟合最佳平面方程,由平面方程插值完成公路路面数据空洞的填补,获得路面数字化初步模型。开展大量实验研究,并与具有代表性的最近邻插值法、克里金插值法、反距离加权插值等算法进行对比,结果表明本方法在计算效率与精度等两个方面都具有优势,是一种可行可靠的方法。 相似文献
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混合总体最小二乘(mixed LS-TLS)合理地顾及了系数矩阵和观测向量误差,却没有考虑数据中可能存在的粗差。利用IGGII方案,提出一种稳健的混合总体最小二乘方法,并通过平面拟合进行验证。结合模拟数据和真实数据,通过与最小二乘(LS)、总体最小二乘(TLS)和混合总体最小二乘的对比分析,证实这种稳健混合总体最小二乘的平面拟合结果最为可靠。 相似文献
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采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的
污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体
污染变化曲线,得出污染物浓度随着远离上游而增加。 相似文献
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Piyoosh Rautela Ramesh Chandra Lakhera 《International Journal of Applied Earth Observation and Geoinformation》2000,2(3-4)
The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies. 相似文献
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ZHAN F. Benjamin 《地球空间信息科学学报》2011,(1)
Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200... 相似文献
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GNSS系统及其技术的发展研究 总被引:3,自引:1,他引:2
阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议. 相似文献
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“4D”技术及其应用 总被引:13,自引:0,他引:13
介绍“4D”(即数字地面模型、数字正射影像、数字栅格地图和数字线划地图)系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。 相似文献
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《International Journal of Digital Earth》2013,6(1):66-87
Abstract Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised. 相似文献
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Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services
Kohei OGAWA Edward VERBREE Sisi ZLATANOVA Naohiko KOHTAKE Yoshiaki OHKAMI 《地球空间信息科学学报》2011,14(2):109-118
Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders. 相似文献